I'm sorry I keep posting cause I really have toooo.. many questions and I'm eager to figure them out.

Here are some questions I met when I was reading Death Note, the manga.

二人の選ばれし者の壮絶な戦いが始まる。死因を書かなければ、全くが心臓麻痺となる。

I copied the above sentences from the manga, but I can't understand parts of them. Firstly, 選ばれし. The しhere is quite confusing. What's its usage here? Or should it be 選ばれる者?Second one is the となる. If I'm right, the grammar is 名詞/形動+になる. So why と here?

keatonatron wrote:となる is simply a more formal/stiff form of になる. The meaning is exactly the same.

Sorry to contradict you, keatonatron, but there is no difference in formality. There is a small difference in meaning. となる implies change to a final state, but になる implies going towards that state. All となる can be になる, but some になる cannot be となる. For example, にぎやかになる or ばかになる can't really change to にぎやかとなる or ばかとなる, because となる implies some kind of finalization.

SS wrote:To add on what've been replied, I just want to say that I've learned that となる and になる are interchangeable in some contexts, but for describing a change of a person as such, になる is more appropriate。

エマ・ワトソンは成人して美人になりました。 Emma Watson has grown up to be a pretty lady.(in this case, she can never get back to a small child, however she will continue to bloom into adulthood)

I can't explain the what the exact rule is yet, but as a native speaker I can give examples of sentences that work and sentences that don't work.

An example of a person's change where you don't use となりました even though it's a final change:エマ・ワトソンは大人になりました。(You usually don't say, エマ・ワトソンは大人となりました。)

Examples of a "final change" involving a person where you can use "となりました":

この映画で、エマ・ワトソンは誰もが知る女優となりました。(With this movie, Ema Watson has became an actress that everyone recognizes.)

ダンブルドアは、帰らない人となりました。(Dumbledore has become a "person of no return" (a euphemism for "dead person") )